HVAC Selector / Temperature Knob Hack

Procedure:

The HVAC core sits between the passenger and driver's side footwells, behind the radio. The evaporator (which chills air for the A/C), the heater core. Most of the levers, flaps, cams and inner workings of the HVAC system are inside. These parts helps mix hot and cold air and direct it out of your floor vents, dash vents or windshield defogger.

The dials for temperature and vent selector are connected to the core through little cables that are prone to break or bind with age or at extreme temperatures. When this happens, you will no longer be able to control the temperature or output vent from the knobs on the dash. The replacement part is expensive and difficult to replace. That's for a different article.

Behind your lower dash in the driver-side foot well, you'll see where both the temperature and selector connect. They look like the picture below, but may be either white or black. Notice the little knob with splines on it. Twisting this will let you adjust your HVAC even if the cables are broken. It is impossible to turn it without some kind of tool.. but don't reach for the pliers just yet!

Here's the clever bit. Firmly grip the non-functioning knob and give it a good tug to pull it off the dash. It'll come off. I promise!

The HVAC knobs are the perfect tool. You don't need pliers or anything. Line up the control knob on the splines, and you can use the knob to manually adjust it.